1. Field
The present disclosure relates to network management. More specifically, the present disclosure relates to a method and system for efficiently distributing and storing network forwarding information.
2. Related Art
The growth of the Internet has brought with it an increasing demand for bandwidth. As a result, equipment vendors race to build larger and faster switches, each capable of supporting a large number of end devices, to move more traffic efficiently. However, the size of a switch cannot grow infinitely. It is limited by physical space, power consumption, and design complexity, to name a few factors. One way to meet this challenge is to interconnect a number of switches to support a large number of users. These interconnected switches can distribute forwarding information among them and store the distributed information in local forwarding tables. However, forwarding tables in such switches can grow substantially with an increasing number of forwarding entries for local and remote end devices. Furthermore, distribution of forwarding information across these switches may become complex and can incur high latency. More importantly, an overly large and complex system often does not provide economy of scale, and distributing and updating information in forwarding tables may become unviable due to the increased complexity.
As layer-2 (e.g., Ethernet) switching technologies continue to evolve, more routing-like functionalities, which have traditionally been the characteristics of layer-3 (e.g., Internet Protocol or IP) networks, are migrating into layer-2. Notably, the recent development of the Transparent Interconnection of Lots of Links (TRILL) protocol allows Ethernet switches to function more like routing devices. TRILL overcomes the inherent inefficiency of the conventional spanning tree protocol, which forces layer-2 switches to be coupled in a logical spanning-tree topology to avoid looping. TRILL allows routing bridges (RBridges) to be coupled in an arbitrary topology without the risk of looping by implementing routing functions in switches and including a hop count in the TRILL header.
While TRILL brings many desirable features to layer-2 networks, some issues remain unsolved when efficient distribution and updating of forwarding information is desired for forwarding tables.